The codes for ADM1 one the FIPS codes, except for the US and Switzerland where ISO codes are used. It is planned to change to ISO codes for more countries.
Lower level ADM codes are using the national code, usually assigned by the national statistical office. (INSEE in France, etc)

The codes for ADM1 one the FIPS codes, except for the US and Switzerland where ISO codes are used. It is planned to change to ISO codes for more countries.
Lower level ADM codes are using the national code, usually assigned by the national statistical office. (INSEE in France, etc)

This would be a fantastic contribution, assuming we are allowed to use the files. Do you know the source and licence of the files?
You can send the polygon files to marc@geonames.org or you can attach them to the forum thread.
I will then update the administrative divisions and also update the web service 'country subdivision' : http://www.geonames.org/export/#countrysubdiv

Hi GeoNames-Team,
Congrats to this really great site. While I tried to add some markers at least for all the villages and towns in my home region, Kanton Schaffhausen, Switzerland, I noticed that in a first step all the tags are issued with country "Germany". Is there any way to fix this?
Cheers, simisa

In border regions the reverse geocoding may use simplified vector information and sometimes locate a place in a neighbouring country. As you have seen you can manually fix it, there is no better solution at this moment.

After reviewing the administrative level 1 codes, I assume that all countries should have a 00 code that represents objects not found within the other administrative divisions. While I disagree with this strategy (IMHO a "null" should be used), I want to make sure that it is correct.

If so I will provide a list of countries that have 00 encoded admin1 attributes but no ADM1 record with a 00 code.

The '00' stands for 'not applicable' where it does not make sense to speak of a admin1 code and 'null' for 'the code is missing or not known'.
However, it is not consequently implemented. Another problem is that some databases (like oracle) don't allow nullable fields in key columns and they need a not-null value to be used with the meaning of 'null'.

I certainly don't need any list as I can do a query on the database myself. If this poses a problem for you then I suggest you convert everything to the value you prefer ('00' or 'null).

I will put a consistency check on the todo list, but it does not have high priority right now.

I saw that 2008 you decided not to include the GOV in the hierarchy for England. Could you revisit that? It would make the hierarchy underneath England a lot more readable plus it is actually used for statistical purposes. Also, my impression is people are using this logic by referring to the "South East" or "North West".

You are the first to show interest in GOV in many years. I still have the impression that the GOV are hardly used anywhere.
The ceremonial counties, in contrast, are used far more often and have higher priority to be included in GeoNames.